High School Mathematics-Physics SMILE Meeting
1997-2006 Academic Years
Teaching Pedagogy

27 October 1998: Ann Brandon [Joliet West HS]
She reviewed the difference between Scalars and Vectors.
She asked which of the following are vectors (V) or scalars (S):
Distance: (S)
Displacement:(V)
Speed:(S)
Velocity:(V)
Acceleration:(V)

She also showed a game in which velocity vectors are illustrated.
There was a sort of maze through which two players should travel in a
race without hitting the walls. They could change the x- and
y-components of velocity by only one unit from the previous move. The
winner goes through in the least number of moves without hitting the
wall.

10 November 1998: Alex Junievicz [CPS Substitute]
He made 2 comments, First he brought a maze that helps get the
difference between Distance/Displacement across. Find the route through
the maze, measure it in meters (expand the relationship of cm to m) and
the figure out the displacement (direct vector route) in meters and
direction. remember North is zero...or use the meteorological ESE
East-South-North-West, etc.

Second, he mentioned a way of keeping electrical meters from being
destroyed. By placing at least 2 silicon diodes in opposite directions
across the movement, thus the voltage should not exceed 0.6 V
saving the meter. if 0.6 V affects the full scale readings, 2
can be put in series--1.2 V. Another device used for protection
is the neon bulb which fires at about 90 V depending upon ambient
light.

06 April 1999: Karlene Joseph [Lane Tech HS]
She asked the question: How do you get a balloon completely inside a
500 cc Florence Flask? The students in her class had various opinions,
which were interesting to consider from the viewpoint of basic physics
and "common sense". She then got a balloon to go inside by putting a
little water [" 50 cc] inside the flask, and boiling away most of it.
Then, she took the flask off the heating element and put the balloon
around the lip of the flask. After a few seconds the balloon was pulled
inside the flask, and as more of the water vapor condensed the balloon
filled up with air. Verrrrrrry interesting!

Next she demonstrated an OCARINA, which she had obtained from the
craft store at Berea College in Berea, Kentucky [Latitude: 37o
34.2', Longitude: 84o 17.6']. She played on octave on the
instrument, and then asked how to explain the sounds from the size and
shape of the holes. Of course, nobody knew!

Addition information has been obtained by Lilla Green [Hartigan
School]

I was in TN for some years and know a little about the Ocarina. It
is sometimes referred to as a "globular flute." I think it is actually
a very ancient instrument, although many cultures have embraced it and
put their own touches to it. I think it originated with Native
Americans, who made them out of clay. Now, they are made from wood or
Terra Cotta or even plastic. They are made in all kinds of shapes, like
animals or faces. The "sweet potato" Ocarina is also common (It's just
shaped like a blob basically). I have seen them in antique stores and
little gift shops, but I have never heard one played. If I were to
guess, though I would say the physics is very similar to the flute or
recorder, where you blow in and change the frequency that comes out by
obstructing various outlets.

--Aubrey T. Hanbicki; The James Franck Institute; University of
Chicago

02 February 1999: Bill Colson [Morgan Park HS]
How is it possible to suck spaghetti into your mouth?

The audience experienced the phenomenon with samples of foul-tasting
pseudo-spaghetti, and drew these conclusions:

There is a pressure difference and the spaghetti will enter the
mouth because the friction of the spaghetti will allow the spaghetti to
be pushed by the pressure difference toward the lower pressure inside
region.

See Readers Digest for January 1999.

01 February 2000: John Scavo (Richards Career Academy)
(handout - see http://www.ed.gov/pubs/parents/Science/soap.html)
placed a pan on the table and filled it half full of water. Then he cut
a small boat shape (about 5 cm long) from an index card. After using a
paper punch to make a hole at the center of the boat, he used scissors
to cut a narrow slot from the back of the boat to the hole - making a
"keyhole" in it. We gathered around to see him place the boat on the
water, and then he squeezed one drop of dishwashing soap into the hole,
and the boat was rapidly propelled from one end of the pan to the
other! A soap-powered boat! Actually, the soap reduces the surface
tension of the water at the back of the boat, and the surface tension
forces on the boat become unbalanced, propelling it. Neat!

14 March 2000: Bill Blunk (Joliet Central HS)
set up the Millikan Oil Drop Experiment on the table. It is a
dandy piece of equipment sold by Sargent Welch, and expensive,
so his school could afford only one, Bill explained. So when he sets it
up for his students, only one at a time can look through the telescope
to see the oil drop(s).

He then showed us a new addition to his technology - a small video
camera that he had bought for $90 at the ISPP
meeting at New Trier
HS. (It's the sort of thing being used on computers these days when
people are "talking" to each other.) It was now connected to a large TV
set in front of us, and when Bill aimed the camera at us, we could see
ourselves on the TV.

He reviewed for us how the Millikan Oil Drop Experiment [http://www.daedalon.com/oildrop.html]
works; a pair of horizontal, parallel conducting plates are placed
about 1 cm apart, and an electric harge is placed on them. Then some
"oil drops" are squirted into the space between them (using an atomizer
with a hollow needle such as for inflating a basketball).

Some of the drops become charged and may have 1, 2, 3, etc electrons
on them. (Millikan used oil drops because he found small water drops
evaporate rapidly, oil drops don't.) With the aid of a dandy diagram on
the board which showed a charged sphere and a rod nearby, Bill showed
us how opposite charges attract and repel. He used colorful magnets
that had the + and - charge signs on them. They stuck to the board on
the diagram and Bill could move them around to show how charges respond
to each other -- a la Bill Shanks.

Bill Blunk also explained that nowadays fairly uniform latex
spheres averaging 913 nm in diameter and carried by water drops
from the atomizer are what he squirts into the space between the
plates. A sphere (drop) with one electron negative charge would be
attracted toward the upper positively charged plate. If a drop had 2
electrons and twice the negative charge (assuming they are all alike),
then it would move twice as fast. By observing the motion of the drops
through the telescope against a reticule (grid), one could calculate
their speeds.

At this point, Bill placed the video camera to "look" right into the
telescope, and we could then see the drops on the TV screen! With the
voltage off (no charge) the drops would gradually move upward (which
was really down, since the telescope inverts the image) under gravity.
But with the voltage on, some would move down (actually, up, as seen on
the TV!). But they moved with different speeds, and the differences
between their speeds was always the same amount, which means that the
electron charges on the drops always differed by the same amount. Bill
could now show this to the entire class at once with the aid of his new
video camera. Great! And it is affordable!

11 April 2000: Carl Martikean (Wallace HS, Gary, IN)
placed a capped jar with a greenish liquid in it on the table, then
wrote on the board: Pediculus humanus capitus. "Does anyone
know that this is?" he asked, referring to the writing. One person
raised her hand. "What's the answer?" asked Carl. To which she replied,
"Head lice!" And Carl said, "Right! Head lice!" Carl said that the
liquid in the jar was sewer water, and twisted off the cap. Then he
opened a plastic bag that he said contained new insects that live in
sewers, and dumped some into the jar of sewer water. "Just look!" Carl
said, pointing to the jar. "They come to life almost immediately!" --
as the particles moved up and down in the jar. "Would anybody like to
drink some of this?" asked Carl. With no volunteers, Carl said, "OK -
I'll drink some myself!" - and much to our disgust and astonishment -
he did! "More?" asked Carl. And then he drank down half the jar. Of
course, by now most of us guessed it was a fake. Carl explained that
the "sewer water" was really a mix of ginger ale (for carbonation) and Frosh
(a soft drink for green color). The "insects" from the plastic bag were
really dried currants. "Kids will believe almost anything you tell
them," Carl said. He explained that he wants his students to question
him (and what they see on TV and elsewhere) about everything, and this
is one way he tries to make skeptics of them.

05 September 2000 Don Kanner (Lane Tech HS)
showed us Galileo's inclined plane experiment. Galileo used a source of
water drops as a clock (equal time intervals between drips) in order to
time how long it took for an object to move down a plane inclined at a
measured angle above the vertical. To have calibrate elapsed time, one
would measure the amount of water collected in 10 seconds. One would do
this for increasing angles of inclination, and make a graph of
acceleration down the plane vs angle of inclination. As the angle
approaches 90 deg (ie, vertical), the acceleration would approach that
of an object in free fall, the acceleration due to gravity, which can
be inferred from extrapolation on the graph. The inclined plane, in a
sense, "dilutes" the acceleration due to gravity so that motion may be
measured over the long time intervals available on a water clock of
that era. Great ideas! Thanks, Don!

10 October 2000 Don Kanner (Lane Tech HS)
showed us a "Test Tube Black Box." He held up a cardboard tube about 45
cm long and 7 cm in diameter. About 2 cm from the
left end, a string passed through the tube through a pair of
diametrically opposed holes. (On each end of the string were
small metal rings to prevent the string from coming free of the tube.)
Another string passed through the tube at its right end, in an
identical manner, except it was longer. Looking at us with a grin, Don
pulled down on the left string, and the string on the right end
shortened. When he pulled down on the right end string, the left end
string shortened. But then he pulled UP on the right end string
- and it moved straight up until it was stopped by its bottom ring. And
the left end string did not become shorter or move at all! How was this
possible!? After showing us again with some variations, Don
challenged us to come up with an explanation or make our own version.
He explained that a chemistry colleague at Lane Tech uses
this to catch the attention of his students and to make them put their
minds to work. So ... how about us!? Any ideas? Maybe Don
will show us more next time.

30 January 2001 Ann Brandon (Joliet West HS)
presented an exercise entitled Millikan's Eggs. The idea is to
determine how many plastic chickens [of identical mass] are inside each
plastic egg [plastic shells of identical mass, not counting the
chickens inside]. The students are to weigh each egg carefully,
and then organize the data in such a form (a bar graph is helpful) as
to determine the number of chickens and the mass of a chicken. If
an egg has n chickens, each of mass m, and if the
plastic shell has mass M, then the mass of that egg will be

Mass(n) = M + n ´
m .

This exercise is analogous to the analysis in Millikan's
Oil Drop Experiment, to determine how many extra electrons are on
an oil drop, and thereby the charge of one electron. The students
found it surprisingly difficult to get started on the analysis.

27 March 2001 Don Kanner (Lane Tech HS, Physics)
mentioned a self-checking graph, associated with the Toilet
Flushing Experiment designed circa 20 years ago by Roy Coleman.
Working in pairs, students were asked to flush a toilet, and to record
the depth of water in the reservoir behind the toilet seat, as a
function of time, in intervals of roughly two seconds. Most
students got a graph like that appearing on the left below, which
resembles a check mark. Upon occasion, student teams would obtain
a graph like the one on the right below. Those students, who had
not followed instructions properly, were measuring water depth in
the wrong chamber!

01 May 2001 Estellvenia Sanders (Chicago Vocational HS) Teeing
for Angles
made a rectangle on the floor about 2 ft wide and 10 ft long using
masking tape. She marked the tape at 1 ft intervals. She then gave each
of three volunteers a toy plastic golf club and plastic ball. Each
volunteer was asked to putt the ball to see the distance it would go
before it either stopped or went out-of-bounds. A chart was drawn on
the board, with each person's name displayed on the vertical-axis, and
the distance on the horizontal-axis. Each distance was located as a dot
on the chart. Straight lines were drawn to connect each pair of dots on
the chart as data was obtained. The lines made various angles with each
other, which the we were asked to identify as obtuse, acute, right
angle, etc. A geometry vocabulary was thus motivated by this game:
angle, point, plane, line, etc. Estellvenia uses hand signing
to communicate with her deaf students, and this kind of activity proves
quite helpful. Thanks, Estellvenia!

25 September 2001 Ann Brandon (Joliet West HS, Physics)Ann gave the following handout sheet of 4 graphs of distance versus
time D-T,
velocity versus time V-T, and acceleration versus time A-T.

Ann continued her presentation of
the 11
September 2001SMILE meeting, in which she dropped a
transparent plastic tennis ball tube,
with washers attached to its
inside bottom end
with rubber bands. Using the Video camera, Jami English
carefully
recorded the tube as it fell through the air, so we could see more
clearly when
and how the washers fell inside the tube. The following tentative
conclusions were made:

It seemed that the washers jump inside the tube after the tube is
dropped, say, 0.5 meters, and well before it hits the floor.

When the tube was thrown up and caught before it started to come
back down, the washers were still pulled inside the tube! It is
the downward acceleration, rather than the downward velocity,
that causes them to be inside. In addition, the upward-moving
tube slows nearly to rest when the washers are pulled inside, making it
easier for our eyes to see it happen.

These conclusions are tentative, pending examination of the video.

11 September 2001: Bill Shanks (Joliet Central HS,
retired)
began a presentation, but promptly discovered that the apparatus was
broken. He will do it next time.

06 November 2001:
Karlene Joseph (Lane Tech HS, Biology) A Measuring Activity
This activity is based on a fairly recent exercise in SMILE
Physics. The idea is, like Galileo in his inclined plane experiments,
to invent our own system of units. She passed out a thin dowel
about 6 inches or 15 cm in length. The length of
the stick is defined as one unit, and for reasons of personal
gratification Karlene named hers one Joseph ---
abbreviated as Jo. Karlene made this stick into a
ruler, and used it to estimate units to the nearest 0.1 Jo, or
tenth of Joseph. Other distances could be expressed in terms of Josephs;
for example, 1 my-unit » 1.4 Jo.

We then measured the lengths, widths, and diameters for other
shapes, expressing the answers in Jo.

As an aid to measurement, Karlene had us hold our sticks at
an angle across ruled notebook paper, so that one end was on a line,
and the other end was lying exactly ten lines below it. We then marked
the stick at each place where it crossed a line. This divided the
stick into 10 equally spaced intervals, and we thus obtained a deci-Joseph
(de-Jo) ruler. We then repeated the measurements described
above, thereby estimating lengths with a precision of hundredths of a Joseph,
or centi-Jo.

Next we calculated the areas of a rectangle, triangle, trapezoid,
and circle, and expressed the answers in square-Josephs, or Jo2.
What a beautiful set of mind-opening ideas for our students!

05 February 2002: Roy Coleman (Morgan Park HS, Physics) Various:

Dropping a Hammer:
A former student, now a lawyer, asked Roy how to describe the
damage done by dropping an 8 lb [3.5 kg] sledge hammer through a height
of about 16 feet [5 meters] onto somebody's skull. They decided
to describe the effect through the work energy theorem. The
potential energy lost by the hammer, mgh, was about 8 lb ´ 16 feet = 128 ft
lb [170 Joules]. Assume that the skull can deform about 1
cm [0.5 in or 1/24 ft] without breaking. The average force
on the skull would then be about 128 ´ 24 lb = 3000 lb [17000 NT].
The skull will surely break under those conditions.

Millikan Eggs:
He described putting a different number of identical objects
(say; marbles) inside various empty Leggs Egg Shell
containers, and then measuring the mass of each of the
containers, to obtain data such as the following [in grams]: 15,
61, 52, 42, 23, 34, 24, 24, 23, 23.Questions: [1] What is the mass of a shell? [2]
What is the mass of each of the identical objects inside? [3]
How many objects are inside each shell? Solution to this problem
is very similar to analysis of data for the Millikan Oil Drop
Experiment to determine the charge of an electron.Porter pointed out that this will not work with real eggs
from chickens, since [1] shells of double yoked eggs are usually
somewhat larger than ordinary shells and [2] You can see inside a
chicken egg by a process known as "candling", or holding the egg over a
shielded bright light. Alas, the day in which each family has a
chicken house and keeps a Bantam Rooster for entertainment
purposes has passed for most Americans.

No Gravity Day [01 April]:
Roy described elaborate and bizarre procedures which were employed on a
recent April 01. Several days in advance, he prepared an
"official announcement" of NO GRAVITY DAY, with an "official
permit" from the "city department of governmental control". He
passed out a sheet with several suggestions for how to manage on that
day, which included the following items:

Do not flush the toilets!

Hold onto the railing on steps!

Obey the traffic signal light on the third floor!

...

... april fool ...

...

Be sure to wear a rope around your wrist.

A hapless substitute math teacher became quite confused after seeing a
staged levitation
experiment, and left school after a few minutes in a quite disturbed
state.

Let's hope the second law of thermodynamics isn't repealed also.
Very
fine, Roy!

05 November 2002: John Bozovsky [Bowen
High School, Physics] Pushing a paper straw through a
potato
John described an experiment in which he pushed one end of an
ordinary
paper straw through a potato, after first putting his finger over the
other
end. Unless you close the other end, the trick will not
work. He
showed the experiment to his daughter, who said "I really hate
science in
school, but I love Physics!" Good point, John!

25 February 2003: Monica Seelman [St James
School] Surface
Tension with Cheerios
Monica has always enjoyed eating Cheerios™ cereal for
breakfast,
and was particularly fascinated by the fact that these pressed toroidal
cereal
pieces tend to clump while floating on milk. How come?
At Monica's
invitation, in groups
of 2, we put some milk into a bowl and began to add a few Cheerios,
which floated on the surface. Monica had expressed some
concern
that she had only been able to get 2% milk, versus her usual skim milk
at
breakfast, and wondered how it would work. We found that it
worked very
well, and that it worked at least as well, and possibly better, with
water. The cereal pieces floated on the surface until they came
close, and
then seemed to stick together along their edges. Presumably, the
surface energy,
which is proportion the surface perimeter between cereal and fluid, is
reduced
by having the cereal pieces to adhere. The same principles apply to
adhesion of
algae in a pond, clotting of blood, etc.

Very interesting --- even though you haven't been eating
your
Wheaties™, Monica!

25 March 2003: Ben Butler[Laura Ward Elementary School,
Science Teacher] What's a Million?
Ben showed several exercises that he has presented to his students.

First he showed us two capped containers [about 2 gallons or
10 liters] that contained colored, tiny plastic beads. He
remarked that each container contained 1 million individual
pieces. The container with yellow beads contained one
black bead. Surprisingly, it was fairly easy to find that
bead, since it migrated to the top as we shook the container. Ben
shook it to the tune of the chorus [Bounce-Bounce-Bounce- ... ]
of the R Kelly rap song, Ignition. without the lyrics. [Ben
occasionally does this chant in class, to let the students know that he
is not totally ignorant of their world.] Ben passed
around another container with a million blue plastic pieces,
and one black one, which is much harder to find.

Ben next showed us the mechanism for a bar stool turntable.
First he used it to demonstrate the relation between the radius R
and circumference c of a circle: c = 2 p
R. He measured the radius (6" or 15 cm) with a ruler,
and then calculated the circumference. He demonstrated the
expression by putting 3 sheets of notebook paper [11" or 33
cm each] around the edge, and then showing that he needs just a
little more to make the circumference [37.7" or 96 cm]

Ben next had a volunteer to stand on the mechanism, and
Ben rotated him around several times. He asked us how far the edge
of the mechanism had moved in, say, 5 complete revolutions --- more
than 15 feet or nearly 5 meters. The participant
got very dizzy while being spun around, for some strange reason!

The volume of a cylinder of radius R and height H
is V = p R2 H, and the
area of its lateral surface is A = 2 p R
H. Starting with two 8.5" ´
11" transparency sheets, Ben folded one into a long,
11" tall cylinder, and the other into an 8.5" short
cylinder. With their bottom ends blocked off, which way cylinder
would hold the greater volume? Most students expect that the
taller cylinder will have a greater volume than the shorter one.
Ben stood both cylinders inside a large transparent container, with the
shorter one encircling the taller one. Then Ben showed us
the answer by using Uncle Ben's Rice™ to fill the long
cylinder completely. He then lifted the long cylinder, so that the rice
inside it spilled into the shorter cylinder --- which was then
only partially filed with rice. Ben was able to add quite a
bit more rice in filling the shorter cylinder! In the interest of full
disclosure, Ben pointed out that he has no relation to either Uncle
Ben™ or his rice!

A good set of ideas, Ben!

25 March 2003: Don Kanner [Lane Tech HS,
Physics]
Proclamation Concerning Areas and VolumesDon remarked that, because the lateral surface area of a
cylinder of radius R
and height H is A = 2 p
R H, whereas its volume is V = p
R2 H,
it should follow that the cylinder of greatest volume for a
given lateral area should be one of large
radius R and very small height H. Do you believe
this?

Don
promised to prove it next time! We await
edification, Don!

08 April 2003: Don Kanner [Lane Tech HS,
Physics] Paradox
and a Pair o' DocksDon had remarked at the last meeting that, because the lateral
surface area of a cylinder of radius R
and height H is A = 2 p
R H, whereas its volume is V = p
R2 H,
it should follow that the cylinder of greatest volume for a
given lateral area should be one of large
radius R and very small height H.
To illustrate the point, Don placed three transparent
cylinders so they stood
upright on the table. One was tall and skinny; it was made from a
single
transparency sheet with its short side (width w) folded around
into a circle
(circumference w) and its long side (height H) standing
up. Its lateral area was
therefore H w. The second (medium) cylinder was only half as
tall, with height
H/2 and circumference 2w, and therefore lateral area of (H/2)
(2w) = Hw,
the same as the tall one. The third cylinder was short and squat,
half as high as the second one, with a height of H/4, and
circumference of
4w, and therefore a lateral area of (H/4) (4w) = Hw, the
same as the first two.
Don arranged them on the table to lie concentrically and coaxial
with each
other, ie., the tall one was surrounded
by the shorter medium one, which in turn was surrounded by the short
squat one,
all standing with a common vertical axis. Their bottom ends were closed
off by
the table, but their top ends were open. What next?

Don poured rice into the tall skinny cylinder in the center,
filling it completely
full to its very top. He pointed out that the volume of the rice must
equal the
volume of the tall skinny cylinder. Then -- beautiful to see! --
Don slowly and
carefully raised the tall cylinder up off the table. As he did so,
the rice
spilled from its now open bottom end to occupy some of the volume
within the
medium cylinder. Don smoothed the rice flat, and we could see
that it filled
the medium cylinder to just half its volume. Wow! So the
medium cylinder must
be capable of holding twice the volume of rice as the tall skinny one!
Finally,
Don slowly raised the medium cylinder to spill the rice from its
bottom end to
occupy some of the volume enclosed within the short squat cylinder.
When he
smoothed the rice flat, we could see that it occupied just 1/4
of the volume of
the short squat cylinder! Don then appealed to the fact that,
if this process is continued indefinitely, the enclosed volume can be
made
arbitrarily large, as is illustrated in the following table, beginning
with a
sheet of height H and width w:

06 May 2003: Roy Coleman [Morgan Park HS,
Physics]
Using Marbles to Determine the Size
of the Monster Behind Door
Roy handed out a sheet containing the following information:

The Size of a Monster

There is a very hungry monster in an almost completely closed
room. There is a door to enter and a thin horizontal
slit at the bottom along the entire
length of a side. Before you enter the room you must
determine the width
of the monster. You also have a large supply of small rocks.

Using a monster
that looks remarkably like a soft drink can and rocks that
look like marbles, you are to determine its experimental
width and compare that value to
its actual width. Each time the monster is hit it
grumbles (klinks?) and
moves, never touching any of the walls.

A couple of hints:

Each group will need to throw at least 200 rocks randomly
through the
slit into the room.

What is the probability of hitting the monster if it is half
the size of the
room?

Look up information on the Rutherford Scattering experiment.

Does the size of the rock itself make a difference?

Good luck in gauging the size of the monster, Roy. Thanks!

09 September 2003: Fred Farnell [Lane Tech HS,
physics]
Balancing an Egg on End
Fred began by describing this activity as an illustration of the
application
of the Scientific Method. He showed a dozen fresh eggs,
which he had asked
his class to vote on the following hypothesis concerning balancing an
egg on
end:

Choices:

Number of Votes

Not possible

45

Only on vernal equinox

34

Only on autumnal equinox

7

Broad end only

35

Pointy end only

1

On either end

10

Only at equator

1

Four eggs were successfully balanced on their broad ends,
by Marilyn Stone and Betty Roombos [twins!].
Others tried to balance the eggs, without success. The moral is
that it requires patience, steady nerves, and effort to balance
an egg. It is also possible to balance an egg on its pointy end. This
question is discussed in the book Bad
Astronomy: Misconceptions and Misuses Revealed, from Astrology to the
moon-landing hoax by Phillip Plait [Wiley 2002, ISBN
0-4714-09766].
Note that some of the choices are not reasonable, such as the fact that
balancing can be done on the vernal equinox, but not on the autumnal
equinox. Still, there are many people who believe in such
pseudo-scientific folklore. For details see the Egg
Balancing
Website: http://www.badastronomy.com/bad/misc/egg_spin.html.

Thanks for sharing this with us, Fred!

23 September 2003: Roy Coleman [Morgan Park HS,
physics]
Pulling on a Spool with a String
Roy brought in a very large wire spool [rough dimensions: outer
diameter
40 cm, inner diameter of 15 cm, height 40 cm].
He wrapped a
heavy cord around the inner portion, and went through the classic
demonstration
of pulling the cord, as described on the website Julien C Sprott:
Physics Demonstrations: Motion
[http://sprott.physics.wisc.edu/demobook/chapter1.htm,
item 1.12]. He made the spool come toward him, go away from him,
stand still
and slip, and slide toward him, just by pulling with various
orientations of the
cord. Roy then rolled the gigantic spool on the chalk tray of
the board, attaching a
marker to the edge. The marker traced a cycloid on the board -- Beautiful!

Bigger spools are better, definitely! Neat, Roy!

Roy also called our attention to the American
Association Physics
Teachers [AAPT] High School Photo
Contest, as described in the Fall
2003
issue oftheAAPT Announcer
[Vol 33, No 3]. [also,
see the
website http://www.aapt.org/Contests/pc03.cfm]
The First Place winner by Jared Hill of Durham NC, is
shown on its
front cover. It shows a hard-boiled egg spinning in a thin
layer of
water. The water is creeping up the side of the egg until it is
thrown
outward, creating a fountain effect. See the journal article "Fluid
flow
up the Wall of a Spinning Egg" by Gutiérrez, Fehr,
Calzadilla, and
Figueroa, American Journal of Physics 66, 442-445 (May
1998). Our
own Ann Brandon is a guiding spirit of this contest!

07 October 2003:
Robert Albert [Roosevelt HS,
science] Observation
and Inference
Robert took out a shopping bag filled with cubes made from empty
milk
cartons -- the cubes had one missing side where the carton tops had
been cut
off. Our cubes were similar, with the numbers 4 and 3 on
the front
and back sides, 1 and 6 on the left and right sides, and 5
on the bottom. All cubes were identical. Each person saw only
the numbers on one cube. We then
were asked to
seek a pattern, to predict what number should have been placed upon the
missing
face. We first saw only the numbers on the sides; since the cubes
were identical, each person had the same information in order to
extrapolate. These numbers represent observations, and it
might be
difficult to suggest a pattern. The possible pattern became more
evident when we
looked at the base, with 5 on it. It was suggested that
the sum of front-back, left-right, and up-down
numbers might be 7, since
4
+ 3 = 7, 1+ 6 = 7 and 2 + 5 = 7. The missing number [2]
could then be predicted from this inference. Of course, that
prediction cannot be confirmed until and unless we see the number on
the missing
side. So it goes with scientific analysis.

Next we replaced the numbers by names:

front-back: hat + fat
sides: bat + cat
bottom-top: mat + ___

What should be written on the top of the cube? Presumably, a
three-letter word,
ending in "at". There were several suggestions:

Presumably, it is a person's first name. These observations may suggest
that the
missing word is a feminine name corresponding to Frank, such as
Franka,
Frances, Francoise, Francene, Francesca, etc. This
puzzle is much
more ill-posed, and the predictions more tentative.

Robert uses this
exercise in class to highlight the difference in observations and
inferences.
You really made us think!

07 October 2003: Imara Abdullah [Douglas Academy,
science]
Posters
Imara provided us with poster paper, colored markers, and tape,
and asked each of
us to prepare a poster to illustrate some concept or process in
mathematics or
science. We came up with the following displays:

Name

Display description

Concept or process illustrated

Porter Johnson

blank sheet of paper

Vacuum, empty space, cosmic void

Bill Colson

Flow chart 3 ® 1

3 conditions for triangle congruence

Roy Coleman

I'm a p r2 (big
wheel)

Area and circumference of circle

Elizabeth Roombos

Rock hurled off cliff

Projectile motion

Marilynn Stone

Click-clack apparatus

Momentum conservation

Monica Seelman

45°-45°-90° triangle

Pythagorean Theorem

Earl Zwicker

Sequential images of ball
on inclined plane

Galileo experiments in mechanics

Imara Abdullah

Walking dog around block

Perimeter

John Bozovsky

Kneeling carpenter drilling into wall

Niels Bohr (kneeling and boring)

Larry Alofs

Rectangle at new IIT student center

Golden rectangle -- or not?

Jane Shields

Colored strips on paper

Northern lights

Babatunde Taiwo

Rocks thrown simultaneously
up and down

Do they hit the ground
at the same time?

Walter McDonald

Headlight beam image

Illumination: Inverse square law

Rich Goberville

Projectile shot from cannon

Action-reaction Forces

Bill Shanks

Plumb bob demons

Universal gravitation

Fred Farnell

Light charged balls on strings

Coulomb's Law: Electrostatics

Leticia Rodriguez

See-through skeleton

Systems in human body

John Bozovsky

Truck accident

How the Mercedes bends

Imara showed us how to display individual posters, using two
sheets of
transparent Plexiglas™ sheets, held by two binder clips. Nifty,
eh!

We were all on our feet and involved! Beautiful Activity, Imara.

04 November 2003: Monica Seelman [ST James Elementary School,
science]
How much paper is there in a roll?
Monica brought a wrapped cylindrical roll of paper about 1.36
meters
in height. The roll had an inner circumference of 11.6
cm, an
outer circumference of 23.6 cm, corresponding to an average
circumference
of 17.6 cm. The thickness of a stack of 25 sheets
was
measured to be 0.6 cm, corresponding 0.024 cm per sheet.
Since the
paper was 2.0 cm thick on the roll, Monica felt that
there were
about 83 sheets in the roll. Thus, she estimated the roll
to be 14.7
meters long --- and with a height of 1.36 meters, this
corresponds to an area of 20
square meters. Larry Alofs suggested an alternative
method of
estimating the amount of paper, by weighing a small piece of paper of
known
area, and then weighing the entire roll. This might have been
more accurate, in
practice. We could have done both, and then rolled the paper out
to see
how long it actually was.

Thanks for showing us the way, Monica!

18 November 2003:
Carol Giles [Collins
HS] INTERNET
EXPERIENCE
Carol
provided us with simulated internet research projects by
dividing us up in
triads, giving each group several "information sheets" on a specific
topic she had
obtained from surfing the net. She asked us to prepare an
overhead transparency
that one of the group members would present to all of us. The following
topics were
considered:

Airbags -- pro and con.

Why do we need librarians?

What are electrolytes?

Stem Cells.

We're better off without computers.

We all enjoyed the discussions which followed the presentations and got
a better
understanding of what our students go through when using the internet
to prepare
reports. Thanks, Carol for such an insightful experience!

09 December 2003:
Brenda Daniel [Fuller Elementary
School]
Science Fair Materials + Scavenger Hunt
Brenda passed around an educators
MAP and other information obtained from the Museum of Science
and
Industry in Chicago [http://www.msichicago.org/].
Using
this information, she led us through two distinct exercises:

Science Fair Materials
Brenda shared her experiences in developing a school science fair [Grades
K-8]. She passed around information on the following topics,
obtained from the Chicago Student Science Fair [http://www.chicagostudentsciencefair.org/]
or the IJAS Science Fair Handbook:

The Scientific Method

How to Do a Science Project

Questions the Judges Might Ask

How to Display a Science Project

Project Ideas

Relevant Illinois Learning Standards

Robert Albert pointed out that the rigid rules of a Science Fair
can actually stifle creative work, in certain cases. Also, he has
often had difficulties in obtaining competent judges for school
science fairs. How is that recurring problem dealt with?

Scavenger Hunt at the Museum of Science and Industry
Brenda passed around a handout: Museum of Science and Industry
Treasure Hunt Questions. Students were given that sheet on a field
trip to MSI, and were kept engaged in thinking, observing, and
looking / searching. Brenda found that these "focus
questions" served to make
the field trip to MSI more meaningful for the students, and
more fun
for all involved. Kids find the typical trip to the Museum to be
boring --- the kids just run around the place and don't learn anything.
The teachers from Brenda's school had visited the Museum ahead
of time,
and had assembled the following questionnaire:
MSI Treasure Hunt Questions

What year was the Isaac Webb ship built? (Ground
floor)

What is the cargo capacity of the Isaac Webb? (Lower
level -- Ships through the ages)

How many orange lockers did you see as you walked into the
museum? (Lower level --more lockers are around the corner)

What animals have already been cloned? (Main floor)

How many stomachs does a cow have? (Farm area)

What are the stomachs called? (Farm area)

How many genetically engineered frogs are there in the
genetic display {Main floor)

How does HIV disrupt the immune system?

What do the letters in AIDS stand for?

When and where did the first Walgreens™ store open?
(Yesterday's main street)

What person from the University of Chicago won the Nobel
Prize for
Literature in 2003 (Cultures of creativity)

What two minority women have won the Nobel Prize?
(Creating cultures --
1st floor)

Who was the first female millionaire in Chicago? (Junior
Achievement -- National
Business Hall of Fame)

Can cloning recreate a person that is dead? (Genetics
decoding life)

What happens to a hotdog 25 years after being buried deep in
a landfill?
(Grainger hall of science)

Why is this museum called the Museum of Science and
Industry? (Main floor
-- rotunda)

What was the first commercial jet designed and built in the
USA? (United 727 --
exhibit)

How much blood is there in a hummingbird's body? (Blood --
balcony exhibit)

What female co-pilot flew around the world with Dick
Rutan in 1986
without refueling the plane? (Flight exhibit)

Before buses were invented, how did people travel from one
town to
another? (Concord coaches)

What is the name of the space center at MSI?

How long does it take to learn how to fly a plane in the U
S Navy? (Navy
room)

Approximately how many times does the heart of a person beat
in a 70 year life
span?

Who developed the solar car?

How much power does it take to operate the solar car?

I am a ship of the Great White Fleet. What is
my name?

I can travel
at a top speed of ___ knots?

What was the year of the first flight?

Approximately how many miles of blood vessels are there in an
adult human body?
(Blood -- balcony exhibit)

Very thought-provoking! Thanks, Brenda.

09 March 2004:
Wanda Pitts [Douglas Elem] Two
Sticklers by Terry Stickels [http://www.terrystickels.com/]
Wanda gave us these two puzzles that she has used in her fifth
grade
classes to stimulate interest in learning:

Q: "The numbers 6009 and 6119 are both
numbers that can be rotated 180° and still be read the
same.
Can you figure out the first number preceding 6009 that holds
this same characteristic?"A: 1961

Q: "How many triangles are there in the figure?"

A: 8 triangles: ABC, ABD, ABE, ABF, ACD, AEF, BCF, BDE

Really good puzzles, Wanda! Thanks.

06 April 2004: John Scavo [Evergreen Park HS,
Physics]
Cub Scout Science
John passed around copies of an article, Amazing Science Tricks
by Michio
Goto, which appeared in the April 2004 issue of Boy's
Life®http://www.boyslife.org/,
official magazine of the Boy Scouts of America®. See
also the book
Amazing Science Tricks by Michio Goto: http://www.thejapanpage.com/html/book_directory/Detailed/329.shtml
. John called particular attention to the lessons
entitled Keeping
Water Separate, A Candle that Sucks Water, Bending
Light through
Water, and Toothpick Torpedo. He demonstrated the
bending of
light through water by poking a hole in a 2 liter soft drink bottle
with an awl,
and then filling it with water. When the bottle was placed on the
table (in
an aluminum oven pan!) in an upright position with the cap off, water
flowed out of the hole in a steady
stream. He held a flashlight at the level of the hole and on the
opposite
side of the bottle, and turned it on. Light shined through the
bottle, and
came out into the stream of water, and was totally reflected internally
along
the stream. Beautiful! He showed us the Toothpick
Torpedo.
First John dabbed a little shampoo on the blunt end of a
wooden
toothpick, and dropped the toothpick horizontally into a pan of water.
The toothpick began
moving in the direction of the sharp end. Why?
Shampoo
reduces the surface tension in the fluid near the blunt end of the
toothpick,
and thus the floating toothpick experiences an unbalanced force, and
goes
forward.

Isn't Science Amazing? Thanks, John

04 May 2004:
Joyce Bordelon [Moos Elementary
School] Simple
Machines
Joyce passed around some information on simple machines, which
contained patterns for each of the six simple machines --the inclined
plane, the
wedge, the lever, the wheel and axle, the pulley, and the screw.
These
template patterns could be cut out
and glued or taped together to make each of the machines. The
information
packet, Simple Machines, was prepared by Carmen O Pagán
and Lily T Reyes,
bilingual teachers at Talcott School. For more information see
the Simple
Machines Learning Site:http://www.coe.uh.edu/archive/science/science_lessons/scienceles1/finalhome.htm.We
discussed the simple machines that are found in various mechanical
systems in
the human body. Levers are present in the arms and the jaw, the
teeth
constitute a wedge, and ball-and-socket joints probably correspond to a
wheel
and axle system.

Interesting points, Joyce!Thanks!

04 May 2004:
Lilla Green [Hartigan Elementary School,
retired] A
Discovery Activity
Lilla fitted three volunteers with blindfolds, and
then gave them a series of items, which they tried to identify only by
touching
and feeling The first item, for example, was a clothespin.
Other
items were balloons, a small piece of play dough, a rubber band, and
various
paper clips. Lilla stated that the Shakers invented
the
clothespin. For more details see the Public Broadcasting Service
website The
Shakers for Educators: http://www.pbs.org/kenburns/shakers/educators/.
Lilla passed out a lesson plan for using clothespins in a
discovery activity, relating to their properties, their history, the
application
of simple machines in the design and construction of clothespins, and
other uses for
them. In particular, she described an exercise for using one or
more
clothespins, along with other materials, to design a useful tool, such
as a bag
closer or a recipe holder. As an extension, she suggested that
the anatomy
of a fish's mouth determines their food source. The fish has to
catch,
hold, chew, and swallow their food.

Very interesting ideas,
Lilla!

07 December 2004: Sally Hill [Clemente
HS] Physics
Catapult Project (handout)
The following has been extracted from the handout passed out by Sally:

Goal: Create a device that will launch a ball at a target
with proper distance and accuracy.

Competition Rules

groups may be no larger than 3 students

you may use any safe materials you wish

no explosives or dangerous air compression devices

your project must be able to fit through a classroom door

you will launch the tennis ball (provided on test date)

the ball must hit the target on a fly

your device must be powered only by energy stored in it, and
may not be aided by a 'helping hand'

Testing Procedure

Each group will line up behind the launching line and send
their tennis ball toward the target 25 feet (8 meters) away.

Each group will be given 3 shots, with each shot graded by
"distance missed"

Sally brought in a winning catapult, and used it to fire a
tennis ball across the room. Stretched fabric was used to provide
the potential energy needed for launch. We found that the
catapult was more powerful when a large, strong rubber band was wrapped
around the pivot point of the catapult -- the tennis ball went about 8
meters across the room.

08 March 2005: Fred Schaal [Lane Tech HS,
mathematics]
RANDINT(1,14,4)+50
Fred used the Pseudo-random Number Generator RANDINT,
which is programmed into the TI-83 calculator.
He generated a random, equally-distributed set of 200 integers from 1
through 14, and obtained the following number-of-occurrences of the
generated numbers:

Generated Number

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Number-of-occurrences

13

12

13

18

17

14

20

15

13

13

17

10

13

12

Does this appear to be a "random" set of numbers? The answer is "Yes",
despite the fact that the number-of-occurrences ranges between 10
and 20. On statistical grounds, we would expect the average number
of occurrences to be about 200/14 = 14.3, with a spread
(standard deviation) of Ö14.3
= 3.8. Thus, about 2/3 of the number-of-occurrences
should lie between 11 and 17. That is consistent with the
spread in the data. Curiously, only the number "6" occurs
exactly 14 times.

Porter Johnson mentioned that "everybody knows" that it is
unlikely for a randomly flipped coin to come up H (Heads) ten
times in a row. However, not everybody realizes that the alternating
sequence H T H T H T H T H T is equally unlikely. Furthermore,
it is quite unlikely that in 1000 coin flips, Heads
will occur exactly 500 times.

Fred also brought in his metal candy box, for which we had taken
exterior measurements last time mp022205.html
to determine a volume of about 910 cm3. We
took a graduated cylinder filled with water, from which we were able to
pour about 800 cm3of water before the box became
full. Our estimated volume was too large by over 10%. Why?

Fred also pointed out that the planet Mercury would
be visible next to the New Moon just after sunset in the next
few days. Thanks for the ideas, Fred!

10 May 2005: Roy Coleman appeared on the Channel 5 (NBC)
news on Monday 09 May. His classroom work with
college-bound students was shown on that program, in keeping with his
wide-spread, well-deserved reputation as an excellent physics teacher. You
looked great, Roy!

18 October 2005:
Betty Roombos (Gordon Tech HS,
physics)
Explore, Plan, and ACT
Betty recently proctored a pre-ACT Plan Test [http://www.act.org/plan/]
-- a practice test for the ACT that is often taken by 10th
graders.
Biology, weathering,
conservation of mass and water, wave-particle model with photoelectric
effect,
and centripetal force were among the topics covered.
Betty felt that this sophomore level test included topics beyond
what
the sophomores should be expected to know. She asked whether the
Plan Test was thus appropriate
for practice. Another concern
was that the students were not given enough time to reason out the
information in
the test -- which was given via complicated charts and graphs. Good
questions! Thanks, Betty.

15 November 2005: Don Kanner (Lane Tech HS,
physics)
Any Questions?
Don showed a strategy for getting class participation. He
handed out
a card to each student. When students asked a question or gave an
answer
(after being called on), he stamped their cards. At the end of
class, the
students put their names on their card, and Don collected
them. Each
stamp on the card was worth extra credit on a future examination.
Students
quickly took an interest in class discussion. Don
illustrated the
strategy using two balloons containing Helium gas. We
asked the
following questions:

Why are the 2 balloons repelling? (like charges repel)

Why are the balloons floating in air? (anti-gravity shields? --
ha)

How do we know that Helium is in the balloons? (Don
inhaled Helium from the balloon and then spoke in a high-pitched
voice.)

The students appreciated getting credit for their participation. Good
ideas! Thanks, Don.

24 January 2006: Don Kanner (Lane Tech,
physics)
Siphoning the net
Don gives students in his classes a chance to redeem themselves
over the
Christmas holidays. He asks them to write paragraphs on 26 items,
such as A: Atwood's Machine, and S: Siphon.
Students should also find a
picture describing the item, as a way of learning to use the internet.
As
examples of how such searching can lead to confusion and
misunderstanding,
Don showed a picture of a siphon found on the net, and the
explanation (text) at this site was riddled with spelling errors—not a
good example for kids. Two other sites had incorrect explanations of
how the siphon works. Cecil Adams
(http://www.straightdope.com/columns/010105.html)
had a rather complete explanation of how siphons work.

21 February 2006:
Roy Coleman (Morgan Park HS,
retired!)
Torques
Roy described a useful way to teach the right hand rule.

t = R ´
F

That is, the torque t is equal to
the cross product of radius
R and
the force F. Let the radius R represent “your
right aRm”,
the force F “your Fingers”, and the torque t
"your thumb".
Point your right aRm in the direction of the first
vector R and its bent Fingers in the direction of the
second
vector F; then the thumb
will point in the
direction of the torque (cross
product).

First he passed around an official Course Planning Assessment
Rubric from the CPS. Bill challenged us to try to
figure out use this rather complicated rubric!

Bill then posed a problem recently discussed in the Straight
Dope column by Cecil Adams in the 03 February 2006 issue of
the Chicago Reader (see the website http://www.straightdope.com/columns/060203.html.
The question has a jet plane sitting on a conveyor belt that is moving
as fast as the plane is going, but in the opposite direction, so that
the plane is
stationary to an outside observer. Does the jet plane take off?
Apparently so! It is true that a jet plane accelerates because of
thrust produced by the engines, whereas there must be friction at the
wheels for an automobile to accelerate. But there was some
skepticism! We
seem not to have reached a consensus on this
problem.

Bill also shared a recent article "Is America Flunking
Science?"
the cover article in the 13 February 2006 issue of Time Magazine®:
http://www.time.com/time/archive/preview/0,10987,1156575,00.html.
Is the USA falling behind other
countries in scientific research? It is suggested that we
need interesting and knowledgeable science teachers in
schools in the earliest grades in order to produce
scientifically interested and literate students.

Thanks, Bill!

18 April 2006: Benson Uwumarogie (Dunbar HS,
Mathematics)
Attempts to Improve Math Scores
Benson
has been attempting to help his students to obtain higher scores
on
standardized tests by assigning questions that are similar in spirit to
those
questions that were "frequently missed" on last years
examinations. The following is a paraphrase (diagrams not
included) of a frequently missed question:

A gardener installs 4 sprinklers (with each centered in the
four quadrants) in a square
plot with sides that are 12 feet long. Each sprinkler waters a
circular
region with a radius of 3 feet. No portion of the plot is watered by
more than 1
sprinkler. What is the approximate area, in square feet, of the
portion of
the plot that is NOT watered by the sprinkler?

This question is rather similar in character to the previous one:

In the doughnut shop, Fred is assigned to put sprinkles on
the chocolate-covered
doughnuts . There are 8 doughnuts on a tray, which don't touch
one
another. Each doughnut has a 4-inch diameter and a 1-inch
hole. The
tray is 20 inches long and 12 inches wide. Fred distributes
sprinkles
randomly and uniformly over the entire tray.

What is the probability that a sprinkle with land on a
doughnut? Explain.

What is the probability that a sprinkle will land on the cookie
sheet?
How is this related to the probability in 1? Explain.

If Fred distributes 4000 sprinkles over the cookie sheet,
predict how many of them
will land on the doughnut. Explain.

This is a reasonable approach to a challenging problem. We hope it
works well! Thanks Benson.

02 May 2006: Nneka Anigbogu (Jones College Prep,
math)
Math Ideas for Non-College
Prep StudentsNneka showed us a way to teach
exponential decay using M&Ms® or Skittles®!
We divided
into three groups, each with a small bag of M&M’s and a
medium sized plastic cup. We counted the number of candies
in our bag and put them into the cup (53-55 were the numbers
to start). Then we shook the cup and tossed the M&Ms
out (like dice) and counted the M&M’s with the M
showing
(heads up). The candy pieces that landed with the M up were
put back into the cup,
which was shaken and tossed once more. Again, about half of them
remained. We continued the process.
Here are the data recorded in tabular form for the groups:

M&M's Toss

Trial Number

Group #1

Group #2

Group #3

1

53

55

54

2

29

25

21

3

14

08

16

4

05

08

07

5

00

04

02

6

-

02

01

7

-

01

00

8

-

00

-

One might expect the number remaining after n tosses, Yn,
to decrease exponentially
with n according to the formula

Yn = Y1 (1 - r)n ...
with r = 1/2.

She drew a graph of the number of M&M’s remaining versus
the number of
tosses, obtaining a profile that looked roughly exponential. She
estimated the parameter
r by using the formula Y2 = Y1 (1 - r),
or

r = 1 - Y2 /Y1

We obtained r = 0.45, 0.55, and 0.57 for the three cases --
the extrapolated
numbers using
these values of r being fairly close to the actual results.